import numpy as np
str='PEMS08.npz'
data=np.load(str)#<numpy.lib.npyio.NpzFile object at 0x00000180FEF77820>
# print(data.items())
# keys = data.keys()
# print(keys)
for key in data.keys():
    # print(key,data[key])
    length = data[key].shape
    print(key,length)#键值，指定键值的形状